19 lines
32 KiB
HTML
19 lines
32 KiB
HTML
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"/><meta name="viewport" content="width=device-width, initial-scale=0.8"/><title>8.6 I/O Patterns</title><link rel="stylesheet" type="text/css" href="../scribble.css" title="default"/><link rel="stylesheet" type="text/css" href="../racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-style.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../doc-site.css" title="default"/><script type="text/javascript" src="../scribble-common.js"></script><script type="text/javascript" src="../manual-racket.js"></script><script type="text/javascript" src="../manual-racket.js"></script><script type="text/javascript" src="../doc-site.js"></script><script type="text/javascript" src="../local-redirect/local-redirect.js"></script><script type="text/javascript" src="../local-redirect/local-user-redirect.js"></script><!--[if IE 6]><style type="text/css">.SIEHidden { overflow: hidden; }</style><![endif]--></head><body id="doc-racket-lang-org"><div class="tocset"><div class="tocview"><div class="tocviewlist tocviewlisttopspace"><div class="tocviewtitle"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,"tocview_0");">►</a></td><td></td><td><a href="index.html" class="tocviewlink" data-pltdoc="x">The Racket Guide</a></td></tr></table></div><div class="tocviewsublisttop" style="display: none;" id="tocview_0"><table cellspacing="0" cellpadding="0"><tr><td align="right">1 </td><td><a href="intro.html" class="tocviewlink" data-pltdoc="x">Welcome to Racket</a></td></tr><tr><td align="right">2 </td><td><a href="to-scheme.html" class="tocviewlink" data-pltdoc="x">Racket Essentials</a></td></tr><tr><td align="right">3 </td><td><a href="datatypes.html" class="tocviewlink" data-pltdoc="x">Built-<wbr></wbr>In Datatypes</a></td></tr><tr><td align="right">4 </td><td><a href="scheme-forms.html" class="tocviewlink" data-pltdoc="x">Expressions and Definitions</a></td></tr><tr><td align="right">5 </td><td><a href="define-struct.html" class="tocviewlink" data-pltdoc="x">Programmer-<wbr></wbr>Defined Datatypes</a></td></tr><tr><td align="right">6 </td><td><a href="modules.html" class="tocviewlink" data-pltdoc="x">Modules</a></td></tr><tr><td align="right">7 </td><td><a href="contracts.html" class="tocviewlink" data-pltdoc="x">Contracts</a></td></tr><tr><td align="right">8 </td><td><a href="i_o.html" class="tocviewselflink" data-pltdoc="x">Input and Output</a></td></tr><tr><td align="right">9 </td><td><a href="regexp.html" class="tocviewlink" data-pltdoc="x">Regular Expressions</a></td></tr><tr><td align="right">10 </td><td><a href="control.html" class="tocviewlink" data-pltdoc="x">Exceptions and Control</a></td></tr><tr><td align="right">11 </td><td><a href="for.html" class="tocviewlink" data-pltdoc="x">Iterations and Comprehensions</a></td></tr><tr><td align="right">12 </td><td><a href="match.html" class="tocviewlink" data-pltdoc="x">Pattern Matching</a></td></tr><tr><td align="right">13 </td><td><a href="classes.html" class="tocviewlink" data-pltdoc="x">Classes and Objects</a></td></tr><tr><td align="right">14 </td><td><a href="units.html" class="tocviewlink" data-pltdoc="x">Units</a></td></tr><tr><td align="right">15 </td><td><a href="reflection.html" class="tocviewlink" data-pltdoc="x">Reflection and Dynamic Evaluation</a></td></tr><tr><td align="right">16 </td><td><a href="macros.html" class="tocviewlink" data-pltdoc="x">Macros</a></td></tr><tr><td align="right">17 </td><td><a href="languages.html" class="tocviewlink" data-pltdoc="x">Creating Languages</a></td></tr><tr><td align="right">18 </td><td><a href="concurrency.html" class="tocviewlink"
|
||
|
|
your program, <span class="stt">"oneline.txt"</span> and <span class="stt">"manylines.txt"</span>.</p><blockquote class="Rfilebox"><p class="Rfiletitle"><span class="Rfilename"><span class="stt">"oneline.txt"</span></span></p><blockquote class="Rfilecontent"><table cellspacing="0" cellpadding="0" class="SVerbatim"><tr><td><p><span class="hspace"> </span><span class="stt">I am one line, but there is an empty line after this one.</span></p></td></tr><tr><td><p><span class="hspace"> </span><span class="stt"></span></p></td></tr></table></blockquote></blockquote><blockquote class="Rfilebox"><p class="Rfiletitle"><span class="Rfilename"><span class="stt">"manylines.txt"</span></span></p><blockquote class="Rfilecontent"><table cellspacing="0" cellpadding="0" class="SVerbatim"><tr><td><p><span class="hspace"> </span><span class="stt">I am</span></p></td></tr><tr><td><p><span class="hspace"> </span><span class="stt">a message</span></p></td></tr><tr><td><p><span class="hspace"> </span><span class="stt">split over a few lines.</span></p></td></tr><tr><td><p><span class="hspace"> </span><span class="stt"></span></p></td></tr></table></blockquote></blockquote><p>If you have a file that is quite small, you can get
|
||
|
|
away with reading in the file as a string:</p><p><div class="SIntrapara">Examples:</div><div class="SIntrapara"><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=define.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define%2529%2529&version=8.6" class="RktStxLink Sq" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktSym">file-contents</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=port-lib.html%23%2528def._%2528%2528lib._racket%252Fport..rkt%2529._port-%7E3estring%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">port->string</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=file-ports.html%23%2528def._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._open-input-file%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">open-input-file</a></span><span class="hspace"> </span><span class="RktVal">"oneline.txt"</span><span class="RktPn">)</span><span class="hspace"> </span><span class="RktPn">#:close?</span><span class="hspace"> </span><span class="RktVal">#t</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=strings.html%23%2528def._%2528%2528lib._racket%252Fstring..rkt%2529._string-suffix%7E3f%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">string-suffix?</a></span><span class="hspace"> </span><span class="RktSym">file-contents</span><span class="hspace"> </span><span class="RktVal">"after this one."</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">#f</span></p></td></tr><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=strings.html%23%2528def._%2528%2528lib._racket%252Fstring..rkt%2529._string-suffix%7E3f%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">string-suffix?</a></span><span class="hspace"> </span><span class="RktSym">file-contents</span><span class="hspace"> </span><span class="RktVal">"after this one.\n"</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">#t</span></p></td></tr><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=strings.html%23%2528def._%2528%2528lib._racket%252Fstring..rkt%2529._string-suffix%7E3f%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">string-suffix?</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=strings.html%23%2528def._%2528%2528lib._racket%252Fstring..rkt%2529._string-trim%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">string-trim</a></span><span class="hspace"> </span><span class="RktSym">file-contents</span><span class="RktPn">)</span><span class="hspace"> </span><span class="RktVal">"after this one."</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">#t</span></p></td></tr></table></blockquote></div
|
||
|
|
reading to a string: the <span class="RktPn">#:close?</span><span class="stt"> </span><span class="RktVal">#t</span> keyword argument ensures
|
||
|
|
that our file is closed after the read.</p><p>We use <span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=strings.html%23%2528def._%2528%2528lib._racket%252Fstring..rkt%2529._string-trim%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">string-trim</a></span> from <a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=strings.html%23%2528mod-path._racket%252Fstring%2529&version=8.6" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket/string</span></a> to remove
|
||
|
|
any extraneous whitespace at the very beginning and very end of our file.
|
||
|
|
(Lots of formatters out there insist that text files end with a single
|
||
|
|
blank line).</p><p>See also <span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=Byte_and_String_Input.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._read-line%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">read-line</a></span> if your file has one line of text.</p><p>If, instead, you want to process individual lines of a file, then you can
|
||
|
|
use <span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=for.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._for%2529%2529&version=8.6" class="RktStxLink Sq" data-pltdoc="x">for</a></span> with <span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=sequences.html%23%2528def._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._in-lines%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">in-lines</a></span>:</p><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=define.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define%2529%2529&version=8.6" class="RktStxLink Sq" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">upcase-all</span><span class="hspace"> </span><span class="RktSym">in</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=for.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._for%2529%2529&version=8.6" class="RktStxLink Sq" data-pltdoc="x">for</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktPn">[</span><span class="RktSym">l</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=sequences.html%23%2528def._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._in-lines%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">in-lines</a></span><span class="hspace"> </span><span class="RktSym">in</span><span class="RktPn">)</span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=Writing.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._display%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">display</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=strings.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._string-upcase%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">string-upcase</a></span><span class="hspace"> </span><span class="RktSym">l</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=Byte_and_String_Output.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._newline%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">newline</a></span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym">upcase-all</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases
|
||
|
|
know how many lines contain “m”, you could do:</p><p><div class="SIntrapara">Example:</div><div class="SIntrapara"><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=file-ports.html%23%2528def._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._with-input-from-file%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">with-input-from-file</a></span><span class="hspace"> </span><span class="RktVal">"manylines.txt"</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=lambda.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._lambda%2529%2529&version=8.6" class="RktStxLink Sq" data-pltdoc="x">lambda</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=for.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._for%252Fsum%2529%2529&version=8.6" class="RktStxLink Sq" data-pltdoc="x">for/sum</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktPn">[</span><span class="RktSym">l</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=sequences.html%23%2528def._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._in-lines%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">in-lines</a></span><span class="RktPn">)</span><span class="RktPn">]</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">#:when</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=strings.html%23%2528def._%2528%2528lib._racket%252Fstring..rkt%2529._string-contains%7E3f%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">string-contains?</a></span><span class="hspace"> </span><span class="RktSym">l</span><span class="hspace"> </span><span class="RktVal">"m"</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktVal">1</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><p><span class="RktRes">2</span></p></td></tr></table></blockquote></div></p><p>Here, <span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=file-ports.html%23%2528def._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._with-input-from-file%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">with-input-from-file</a></span> from <a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=port-lib.html&version=8.6" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket/port</span></a> sets
|
||
|
|
the default input port to be the file <span class="stt">"manylines.txt"</span> inside
|
||
|
|
the thunk. It also closes the file after the computation has been
|
||
|
|
completed (and in a few other cases).</p><p>However, if you want to determine whether “hello” appears in a file,
|
||
|
|
then you could search separate lines, but it’s even easier to simply
|
||
|
|
apply a regular expression (see <a href="regexp.html" data-pltdoc="x">Regular Expressions</a>) to the stream:</p><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=define.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define%2529%2529&version=8.6" class="RktStxLink Sq" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">has-hello?</span><span class="hspace"> </span><span class="RktSym">in</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=regexp.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._regexp-match%7E3f%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">regexp-match?</a></span><span class="hspace"> </span><span class="RktVal">#rx"hello"</span><span class="hspace"> </span><span class="RktSym">in</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym">has-hello?</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=stringport.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._open-input-string%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">open-input-string</a></span><span class="hspace"> </span><span class="RktVal">"hello"</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">#t</span></p></td></tr><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym">has-hello?</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=stringport.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._open-input-string%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">open-input-string</a></span><span class="hspace"> </span><span class="RktVal">"goodbye"</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">#f</span></p></td></tr></table></blockquote><p>If you want to copy one port into another, use <span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=port-lib.html%23%2528def._%2528%2528lib._racket%252Fport..rkt%2529._copy-port%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">copy-port</a></span> from
|
||
|
|
<a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=port-lib.html&version=8.6" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket/port</span></a>, which efficiently transfers large blocks
|
||
|
|
when lots of data is available, but also transfers small blocks
|
||
|
|
immediately if that’s all that is available:</p><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=define.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define%2529%2529&version=8.6" class="RktStxLink Sq" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktSym">o</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=stringport.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._open-output-string%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">open-output-string</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=port-lib.html%23%2528def._%2528%2528lib._racket%252Fport..rkt%2529._copy-port%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">copy-port</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=stringport.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._open-input-string%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">open-input-string</a></span><span class="hspace"> </span><span class="RktVal">"broom"</span><span class="RktPn">)</span><span class="hspace"> </span><span class="RktSym">o</span><span class="RktPn">)</span></td></tr><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="https://download.racket-lang.org/releases/8.6/doc/local-redirect/index.html?doc=reference&rel=stringport.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._get-output-string%2529%2529&version=8.6" class="RktValLink Sq" data-pltdoc="x">get-output-string</a></span><span class="hspace"> </span><span class="RktSym">o</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">"broom"</span></p></td></tr></table></blockquote><div class="navsetbottom"><span class="navleft"><form class="searchform"><input class="searchbox" id="searchbox" type="text" tabindex="1" placeholder="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, "8.6", "../");"/></form> <a href="https://docs.racket-lang.org/index.html" title="up to the documentation top" data-pltdoc="x" onclick="return GotoPLTRoot("8.6");">top</a><span class="tocsettoggle"> <a href="javascript:void(0);" title="show/hide table of contents" onclick="TocsetToggle();">contents</a></span></span><span class="navright"> <a href="encodings.html" title="backward to "8.5 Bytes, Characters, and Encodings"" data-pltdoc="x">← prev</a> <a href="i_o.html" title="up to "8 Input and Output"" data-pltdoc="x">up</a> <a href="regexp.html" title="forward to "9 Regular Expressions"" data-pltdoc="x">next →</a></span> </div></div></div><div id="contextindicator"> </div></body></html>
|